The invention relates to a disposable injector with a housing in which or on which are arranged, in each case at least in some areas, at least one mechanical spring energy reservoir, at least one cylinder/piston unit that can be filled at least temporarily with active substance, at least one piston-actuating ram and at least one trigger unit, wherein the piston-actuating ram is positioned between the spring energy reservoir and the piston of the cylinder/piston unit, wherein the spring energy reservoir comprises at least one pretensioned spring element, wherein the spring-loaded piston-actuating ram is supported on the housing via support rods or tension hooks, and wherein the contact zone situated between an individual support rod or tension hook and the piston-actuating ram represents a wedge gear pairing that forces the respective support rod or tension hook outwards.
DE 10 2007 031 630 A1 discloses, among other things, an injector of this type. With the exception of the mechanical spring of the spring energy reservoir, almost all the components of the injector are produced expensively from plastics by injection moulding. Components that are subject to high mechanical loads are additionally reinforced with glass fibres.
DE 10 2007 008 369 A1 discloses a one-way injector with a housing in which, or on which, —in each case at least over some part thereof—a mechanical spring energy store, at least one cylinder piston unit which at least at times is filled with an effective medium. At least one piston operating plunger and at least one release unit is arranged, wherein the spring-energy store comprises at least a pre-tensioned spring element and wherein at least part of the piston operating plunger is positioned between the spring energy store and the piston of the piston-cylinder unit. The spring-loaded piston operating plunger has at least one pull rod which has a support surface in the area of its rear end. At the support surface or surfaces, locking elements are supported on the housing whose locking position is secured by a release element which is secured in a blocking position. The release element has a release position which results in a release of the locking elements.
WO 2005/044 344 A1 discloses an arrangement for delivering an injectable product which arrangement includes a housing, a product container accommodated in the housing, a piston rod for moving the piston in the forward direction and a spring acting on the piston rod in the forward direction. The product container is supported so as to be moveable and includes a piston which is supported so as to be moveable in the forward direction for the emission of a product. The piston rod is supported, against the force of the spring, releasably in a holding position in a holding engagement so as to be releasable however. The spring extends in the holding position into the container.
Therefore, the problem addressed by the present invention is that of developing a disposable injector of modular design which, with a small overall size, comprises only a small number of components and, while being easy to handle and inexpensive to produce, ensures safe storage and operation.